import numpy as np
a=np.array([[1,2,3],[4,5,6],[7,8,9],[10,11,12]])
print('4*3的整数数组: \n',a)
print('数组的ndim属性: ',a.ndim)
print('数组的shape属性: ',a.shape)
print('数组的size属性: ',a.size)
print('数组的dtype属性：',a.dtype) 